Wow - you have had A LOT to deal with this last week. I am so sorry that your little guy is sick.
I know it's been very difficult and I'm sorry that you've had a rough go at it. You are doing exactly what you need and should be doing for your little guy. I know this is trying your patience, and making you second-guess your decision to buy him, but think about what he would happen if he didn't have somebody as loving and caring as you to take care of him? Take comfort in that you and he were brought together for a reason, and he is depending on you to help him through this.
When my Min Pin got sick last year, I had no idea what was going on with her. She was lethargic, wasn't eating, making messes in the house (she was 10 at the time) and my husband and I were at a loss as to what was going on. We were constantly cleaning up after her, our carpets were getting trashed, and our hardwood floors were getting demolished. I knew something was wrong with her, so after a couple days of this going on, we finally took her to the vet. My worst fears were confirmed - she had developed pyometra (my husband never had her spayed - I was with him for about a year at that time), and as a result, she devloped an infection in her uterus. The vet told us that she needed to be operated on right away (in the next 2-3 days) or she would die. They were going to charge us $1300 for the operation and I knew we couldn't have afforded that. I have never felt more helpless in my life. We told the vet that we couldn't afford the surgery and we tearfully left the clininc w/o knowing what we were going to do to save her. But instead of giving up, I knew that we had to protect and save her at all costs - I was not going to give up.
I used the internet to research low-cost clinics that might be able to help. After searching for about 3 hours that night, my prayers were answered and I found a clinic that could do her ovariahysterectomy (sp) for about $350. That was certainly more managable than $1300, and I made an appt to bring her in the next day. The day of her surgery was the longest day of my life - I took at day off from work, and made the hour trip to the clinic for her operation. I got there, filled out the paperwork and I was a nervous wreck. They weighed her and took her back, and I never got a chance to say good-bye. I have NEVER cried so much in my life as I did that day. I patiently waited by the phone for an update on her surgery, and alas, at 4:00 that afternoon, the vet called me and said she was fine and all was a success.
The next week, our vet examined her and found a fatty substance under her front leg - almost looked like a big bug bite, although, it was not as simple as a bug bite. To spare you with the long details, we found out that she has Stage II mammory tumors which have attached themselves to her body. We elected to have her go through another surgery (2 weeks after her hysterectomy) to remove one of the tumors and have it fully tested. My poor girl went through two major operations in two weeks and it tried my patience & faith like no other. It was also the worst two weeks of my life.
Why am I telling you all of this? Because I want you to see that we all have had those trying and challenging times were we question ourselves, our judgement, our ability to make good decisions. It's in those times in which you really find out your strengths. The only thing that kept me going through Shelby's (Min Pin) ordeal is that we made a committment to her to provide and take care of her, at no cost. I could not let her down.
You must not let Django down - he is depending on you. Keep your head up, persevere through this, and use DT members for support and guidance. We are pulling for you two, and I sincerely hope he gets well and has a happy life with you. You're doing a great job. Keep telling yourself "One day at a time".
Feel free to PM me directly if you ever want to talk or vent.

We're here for you.
Heather